Golf putting trainer

ABSTRACT

Provided is a putting-training tool for enabling a user to train the putting while realizing that the error of a ball hitting angle may be confined within about 2 degrees. The putting-training tool is characterized in that a golf ball rolling groove has a width of 9 mm to 5 mm and has a transverse section gently-recessed into a curved face for supporting a golf ball at one point, so that the golf ball may not leave, in case a putting force to roll the golf ball by about 1.5 m to 2 m on the green is applied, the golf ball rolling groove for errors of the ball hitting angle less than 2 degrees.

TECHNICAL FIELD

The present invention relates to a golf putting trainer.

BACKGROUND ART

As shown in FIG. 10, in practicing golf putting, a golfer has an effective practice in which the golfer uses a putter P to hit a golf ball B toward a hole H at a distance of about 1.5 m from the hole H.

In consideration of the hole H having diameter of about 107.9 mm, as shown in FIG. 10, the struck golf ball B has a chance to go in hole H when an internal angle θ (hereinafter referred to as error θ of a ball hitting angle) formed between an actual hitting direction U of the golf ball B and a straight line L connecting the hole H and the golf ball B placed at a hitting position is not more than about 2 degrees.

On the other hand, a golf putting trainer has been proposed. FIG. 11 shows an outline of a golf putting trainer 100 disclosed in Patent Document 1. FIG. 12 shows a transverse section of FIG. 11.

Patent Document 1: Japanese Patent Publication Laid-Open No. H9-234262A

The putting trainer 100 has a configuration in which a rail 102 is provided on a base 101. It is assumed that a hole is located on an extension of the rail 102, and the golfer practices hitting a golf ball B straightforward toward the hole such that the golf ball B does not drop out from the rail 102.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, the golf putting trainer 100 disclosed in Patent Document 1 is not intended to practice putting such that the error of the ball hitting angle falls within about 2 degrees or less. Therefore, the golf putting trainer 100 cannot be used when the golfer practices putting while taking notice that the ball hitting angle falls within about 2 degrees or less.

In view of the foregoing, an object of the invention is to provide a putting trainer in which the golfer can practice putting while taking notice that the ball hitting angle falls within about 2 degrees or less.

Means for Solving the Problems

The invention according to claim 1 is a golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along the ball rolling groove, characterized in that the ball rolling groove has a groove width of 9 mm to 5 mm, a transverse sectional shape of the ball rolling groove is formed into a gently concave curved surface in which the golf ball is supported at one point, and a percentage in which the golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force with which the golf ball is rolled to about 1.5 m to 2 m on green is applied.

The invention according to claim 2 is a golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along the ball rolling groove, characterized in that the ball rolling groove has a groove width of 12 mm to 10 mm, a transverse sectional shape of the ball rolling groove is formed into a gently concave curved surface in which the golf ball is supported at one point, and a percentage in which the golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error not more than 2 degrees when a putting force, with which the golf ball is rolled to about 1.5 m to 2 m on the green, is applied.

In the golf putting trainer according to claim 1 or 2, the invention according to claim 3 is characterized in that the curved surface is formed into an arc surface whose section becomes an arc shape.

In the golf putting trainer according to any one of claims 1 to 3, the invention according to claim 4 is characterized in that the curved surface is formed into an elliptical surface whose section becomes an elliptical shape.

In the golf putting trainer according to claim 1 or 2, the invention according to claim 5 is characterized in that the curved surface includes a flat surface located in a groove bottom of the ball rolling groove and a slope rising from both sides of the flat surface.

In the golf putting trainer according to any one of claims 1 to 5, the invention according to claim 6 is characterized in that flat trimming surfaces are provided along groove edges on both sides of the ball rolling groove.

In the golf putting trainer according to claim 6, the invention according to claim 7 is characterized in that a downward sloping surface is formed from an edge of the flat surface to an edge of a plate material.

In the golf putting trainer according to any one of claims 1 to 7, the invention according to claim 8 is characterized in that at least one ball rolling groove is lusterless inside.

In the golf putting trainer according to any one of claims 1 to 8, the invention according to claim 9 is characterized in that a mark having a diameter smaller than a diameter of the golf ball is provided around the ball placing portion.

The invention according to claim 10 is a golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along the ball rolling groove, characterized in that a transverse sectional shape of the ball rolling groove is formed into an arc shape having a curvature radius of 100 mm, the ball rolling groove has a groove width of 1.5 mm to 5 mm, and a percentage in which the golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force, with which the golf ball is rolled to about 1.5 m to 2 m on the green, is applied.

The invention according to claim 11 is a golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along the ball rolling groove, characterized in that a transverse sectional shape of the ball rolling groove is formed into an arc shape having a curvature radius of 60 mm, the ball rolling groove has a groove width of 9 mm to 5 mm, and a percentage in which the golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force, with which the golf ball is rolled to about 1.5 m to 2 m on the green, is applied.

In the golf putting trainer according to any one of claims 1 to 11, the invention according to claim 12 is characterized in that the golf putting trainer is made of a metal.

EFFECTS OF THE INVENTION

Using the putting trainer according to claim 1, a professional and an advanced-level amateur golfer can accurately practice their putting such that the error of the ball hitting angle is lower than 2 degrees.

Using the putting trainer according to claim 2, a beginner and an intermediate golfer can practice putting such that the error of the ball hitting angle is not more than 2 degrees.

According to the invention in claim 3, the ball rolling groove can be formed by providing the groove whose section is formed into the arc shape in the upper surface of the base.

According to the invention in claim 4, the ball rolling groove can be formed by providing the groove whose section is formed into the elliptical shape in the upper surface of the base.

According to the invention in claim 5, the inclination of the slope can be adjusted such that the golf ball does not break away from the rolling groove when the error of the ball hitting angle is lower than 2 degrees or not more than 2 degrees.

According to the invention in claim 6, the flat trimming surfaces are provided along the edges of the ball rolling groove to highlight the existence of the ball rolling groove, which allows the golfer to concentrate nerves on the ball rolling groove.

According to the invention in claim 7, the golf ball breaking away from the ball rolling groove is rolled on the downward sloping surface, which allows the golfer to clearly see the golf ball breaking away from the ball rolling groove.

According to the invention in claim 8, because the ball rolling groove has a lusterless surface, the golf ball can be rolled in the ball rolling groove while slipping of the golf ball is prevented.

According to the invention in claim 9, an address stance is corrected such that a positional relationship between the golf ball and the mark becomes proper, which allows the golfer to take the proper address stance.

According to the invention in claim 10, using the putting trainer, the golfer practices putting such that the golf ball does not break away from the ball rolling groove, which allows the ball hitting angle to become lower than 2 degrees. In the putting trainer, the ball rolling groove is formed, and the ball rolling groove has the arc-shape transverse section, the curvature radius of 100 mm, and the groove width of 9 mm to 5 mm.

According to the invention in claim 11, using the putting trainer, the golfer practices putting such that the golf ball does not break away from the ball rolling groove, which allows the ball hitting angle to become lower than 2 degrees. In the putting trainer, the ball rolling groove is formed, and the ball rolling groove has the arc-shape transverse section, the curvature radius of 60 mm, and the groove width of 9 mm to 5 mm.

Accordingly, in the invention according to claim 12, the golf putting trainer can accurately be molded with an extrusion molding die.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a plan view of a putting trainer according to an embodiment of the invention. FIG. 2 shows a transverse section of FIG. 1.

As shown in FIG. 1, a base 2 of a golf putting trainer 1 is formed into a long plate shape. In an upper surface of the base 2, a ball rolling groove 3 is formed toward a lengthwise direction in the center of a width direction of the base 2. As shown in FIG. 1, the ball rolling groove 3 can be formed from a base end of the base 2 to a leading end. Alternatively, the ball rolling groove 3 may be formed from an arbitrary position on a base-end side of the base 2 to the leading end of the base 2.

As shown in FIG. 1, the ball rolling groove 3 is formed so as to have the same groove width from the base end to the leading end. As shown in FIG. 2, the transverse section of the ball rolling groove 3 is formed into an arc shape.

A ball placing portion 4 is formed on the base-end side of the ball rolling groove 3. The ball placing portion 4 is a region where the golf ball B is placed in address. The golf ball B placed on the ball placing portion 4 is hit along the ball rolling groove 3. The ball placing portion 4 includes a hole 5 which pierces through a surface to a backside of the base 1 and a circular mark 6 provided around the hole 5. A diameter of the hole 5 is smaller than a diameter of the golf ball B such that the golf ball B is placed on the ball placing portion 4 without dropping out from the ball placing portion 4. A diameter of the mark 6 is slightly smaller than the diameter of the golf ball B shown by an alternate long and two short dashes line of FIG. 1, and the mark 6 and the hole 5 are provided in a concentric fashion. The color such as black can be given to the mark 6. The mark 6 is required in taking a proper address stance.

That is, for example, a right-handed golfer sees the golf ball B with the left eye from immediately above the golf ball B placed on the ball placing portion 4, and the golfer corrects the stance thereof so as not to be able to see the mark 6 in all circumferences. Therefore, the golfer can take the proper address stance.

As shown in FIG. 2, in the case where the ball rolling groove 3 is formed into an arc transverse sectional shape, a numerical value not lower than a radius of the golf ball B is taken for a curvature radius of the transverse section of the ball rolling groove 3 such that the golf ball B can be supported at one point while the golf ball B is placed in the ball rolling groove 3 as shown in FIG. 3. The dimensions such as a groove width, a depth, and a curvature radius of the ball rolling groove 3 are set at numerical values such that the golf ball B does not break away from the ball rolling groove 3, when the error θ of the ball hitting angle is lower than 2 degrees as shown in FIG. 1. The specific numerical values of the dimensions such as a groove width, a depth, and a curvature radius of the ball rolling groove 3 are described later.

As shown in FIG. 1, trimming surfaces 7 and 7 are formed along the lengthwise direction at groove edges on both sides of the ball rolling groove 3. The trimming surface 7 is formed into a flat surface. The trimming surfaces 7 and 7 are connected to sloping surfaces 8 while steps 7 a are interposed therebetween, and the sloping surface 8 is connected to base 1 while inclined downwards.

At least the ball rolling groove 3 has a lusterless surface, and the ball rolling groove 3 has a surface structure in which a slip of the golf ball B can be prevented. The whole surface of the base 2 including the golf ball rolling groove 3 may be formed lusterless. Pear skin can be cited as an example of the lusterless means.

FIGS. 4 to 6 are tables showing results of experiments in which the golf ball B is hit for ball rolling grooves 3 having different dimensions.

In the case of FIG. 4, the ball rolling groove 3 has a length of 100 cm, and the ball is mechanically hit using a well-known apparatus with a putting force with which the ball can be rolled on the green to 150 cm or 180 cm. In other words, FIG. 4 shows the case in which the golf ball B is hit with the putting force corresponding to a force with which the golf ball B is actually putted on the green. FIG. 4 shows the experimental result in the case where the ball rolling groove 3 has the curvature of 100 mm in the transverse section, the groove width of 3 mm to 12 mm, and the groove depth of 0.011 mm to 0.180 mm.

As shown in FIG. 1, in the experiment for hitting the golf ball B, the golf ball B placed on the ball placing portion 4 is hit such that the error θ of the ball hitting angle becomes 0, 1, and 2 degrees, thereby making a determination whether or not the golf ball B breaks away from the golf ball rolling groove 3. The experiment shows the case in which the golf ball B placed on the ball placing portion 4 is mechanically hit using a well-known apparatus with the putting force with which the golf ball B is rolled to about 1.5 m to 2 m. That is, the experiment shows the case in which the golf ball B is hit with the putting force corresponding to a force with which the golf ball B is actually putted on the green.

In the table of FIG. 4, a mark “X” indicates that the golf ball B breaks away from the ball rolling groove 3, and a mark “◯” indicates that the golf ball does not break away from the ball rolling groove.

FIG. 5 shows the experimental result similar to that of FIG. 4 in the case where the ball rolling groove 3 has the curvature of 60 mm in the transverse section, the groove width of 3 mm to 12 mm, and the groove depth of 0.019 mm to 0.301 mm.

FIG. 6 shows the experimental result similar to that of FIG. 4 in the case where the ball rolling groove 3 has the curvature of 180 mm in the transverse section, the groove width of 3 mm to 12 mm, and the groove depth of 0.006 mm to 0.100 mm.

As shown in FIGS. 4 and 5, in the case where the error θ of the ball hitting angle is lower than 2 degrees while the groove width of the ball rolling groove 3 ranges from 5 mm to 9 mm, the percentage in which the golf ball B breaks away from the ball rolling groove 3 is small. However, the percentage in which the golf ball B breaks away from the ball rolling groove 3 becomes large in the case where the error θ of the ball hitting angle is higher than 2 degrees.

Therefore, in the case where the groove width of the ball rolling groove 3 ranges from 5 mm to 9 mm, the golf ball B is hit so as not to break away from the ball rolling groove 3, whereby the golfer can practice putting while taking notice that the error θ of the ball hitting angle is lower than 2 degrees. Thus, the golfer practices putting such that the error θ of the ball hitting angle is lower than 2 degrees, whereby the golfer probably sinks the golf ball B in the hole on the actual green. Thus, the golfer practices accurate putting such that the error θ of the ball hitting angle is lower than 2 degrees is suitable to training professional and advanced-level amateur golfers.

As shown in FIGS. 4 and 5, the percentage in which the golf ball B breaks away from the ball rolling groove 3 is small, in the case where the error θ of the ball hitting angle is not more than 2 degrees while the groove width of the ball rolling groove 3 ranges from 10 mm to 12 mm.

Therefore, in the case where the ball rolling groove 3 has the curvature radius of 60 mm or 100 mm and the groove width of 10 mm to 12 mm, the golfer has the practice in which the golfer hits a golf ball B such that the golf ball B does not break away from the ball rolling groove 3, whereby the golfer can practice putting while taking notice that the error θ of the ball hitting angle is not more than 2 degrees. The golfer practices putting such that the error θ of the ball hitting angle is not more than 2 degrees and thus suitable for training beginner and intermediate golfers.

As shown in FIG. 6, in the case where the ball rolling groove 3 has the curvature radius of 180 mm and the groove width of 9 mm to 12 mm, the percentage in which the golf ball B breaks away from the ball rolling groove 3 is small when the error θ of the ball hitting angle is lower than 2 degrees. However, the percentage in which the golf ball B breaks away from the ball rolling groove 3 will become large, when the error θ of the ball hitting angle is not lower than 2 degrees.

Therefore, in the case where the ball rolling groove 3 has the curvature radius of 180 mm and the groove width of 9 mm to 12 mm, the golfer has the practice in which the golfer hits a golf ball B such that the golf ball B does not break away from the ball rolling groove 3, whereby the golfer can practice putting while taking notice that the golf ball B is probably sunk in the hole on the actual green because of the ball hitting angle having the error θ lower than 2 degrees. The accurate putting training is suitable for professional and advanced-level amateur golfers.

In the above-described experiments, the experiment is not performed between the curvature radius of 60 mm (shown in FIG. 4) and the curvature radius of 100 mm (shown in FIG. 5). However, in the case where the golf ball rolling groove 3 has the same groove width, the groove depth becomes shallower as the curvature radius is enlarged, and the golf ball B easily breaks away from the ball rolling groove 3. However, the similar experimental result is obtained in the case of the curvature radius of 60 mm (shown in FIG. 4) and in the case of the curvature radius of 100 mm (shown in FIG. 5). Therefore, it is determined that the similar experimental result is obtained at least between the curvature radius of 60 mm (shown in FIG. 4) and the curvature radius of 100 mm (shown in FIG. 5).

In other words, as described in claim 1, when the putting force with which the golf ball is rolled to about 1.5 m to 2 m on the green is applied, the shape having the small percentage in which the golf ball B breaks away from the ball rolling groove 3 while the error θ of the ball hitting angle is lower than 2 degrees corresponds to the ball rolling groove 3 having the circular transverse sectional shape, the groove width of 5 mm to 9 mm, and the curvature radius of 60 mm to 100 mm.

As shown in FIG. 6, in the case where the ball rolling groove 3 has the curvature radius of 180 mm and the groove width of 9 mm to 12 mm, the percentage in which the golf ball B breaks away from the ball rolling groove 3 is small when the error θ of the ball hitting angle is lower than 2 degrees. Therefore, the ball rolling groove 3 having the ranges corresponds to the ball rolling groove according to claim 1.

As described in claim 2, when the putting force with which the golf ball is rolled to about 1.5 m to 2 m on the green is applied, the shape having the small percentage in which the golf ball B breaks away from the ball rolling groove 3 while the error θ of the ball hitting angle is not more than 2 degrees corresponds to the ball rolling groove 3 having the circular transverse sectional shape, the groove width of 10 mm to 12 mm, and the curvature radius of 60 mm to 100 mm. In the case of the curvature radius of 100 mm, the shape in which the groove width of the ball rolling groove 3 ranges from 10 mm to 12 mm can satisfy the requirements. In the case where the ball rolling groove 3 has the above-described mode, the putting training is suitable for the beginner and intermediate golfer.

Next, the action will be described. As shown in FIG. 3, the golf ball B is supported at one point by the ball rolling groove 3. Therefore, the golf ball B is rolled in the ball rolling groove 3 along an axial center direction of the ball rolling groove 3 while unstably and easily rolled in a width direction of the ball rolling groove 3. Additionally, due to the fact a side face 3 a of the ball rolling groove 3 is formed into an uphill sloping surface, a drawing-back force F acts on the golf ball B so as to draw back the golf ball B toward the center direction of the ball rolling groove 3 based on the gravity acting on the golf ball B, when the golf ball B breaks away from the ball rolling groove 3. The drawing-back force F reproduces the status in which the golf ball B is actually rolled on the green.

In other words, as shown in FIG. 7, in the case where the golf ball B is curved leftward on the actual green, the golf ball B is rolled while bending down the lawn S. At this point, the golf ball B is subject to a reactive force M shown by an arrow from the rising lawn S. This state is continued while the golf ball B rolls forward swaying right and left. The reactive force M shown by the arrow corresponds to the drawing-back force F of FIG. 3. Thus, in the embodiment, due to the fact that the golf ball B is rolled forward while swaying right and left in the golf ball rolling groove 3, the golf ball B is brought close to the state in which the golf ball B is rolled on the actual green, and the golfer can practice putting while feeling a realistic sensation. Additionally the ball rolling groove 3 is formed lusterless. Therefore, the golfer can practice putting in a sense close to the case in which the golfer sinks the putt on the lawn by a synergistic effect of the lusterless effect and the effect of the one-point support structure.

As shown in FIGS. 4 to 6, the ball rolling groove 3 has the groove width as thin as 12 mm or less, and the flat trimming surface 7 is provided along the grove edge of golf ball rolling groove 3, and the trimming surface 7 is visible while floating from the sloping surface by the step 7 a. Therefore, the golfer can practice the putting while seeing the thin ball rolling groove 3 having the thin width and the trimming surfaces 7 and 7 to concentrate nerves on the ball rolling groove 3.

Additionally the downward sloping surface 8 is formed from the trimming surface 7 to the edge of the base 2. Therefore, when the golf ball B breaks away from the ball rolling groove 3, the golfer sees the golf ball B rolling down in the sloping surface 8, so that the golfer can clearly recognize that the golf ball B breaks away from the ball rolling groove 3.

FIG. 8 shows a second embodiment. The second embodiment is characterized in that the transverse sectional shape of the ball rolling groove 3 is formed into an elliptical shape. In the second embodiment, because the transverse sectional shape of the ball rolling groove 3 is formed into the elliptical shape, a slope 12 rising from a groove bottom 11 of the ball rolling groove 3 has a curvature radius smaller than a curvature radius of the groove bottom 11.

The curvature radius in the transverse section of the ball rolling groove 3 is a main factor defining whether or not the golf ball B drops out from the ball rolling groove 3. The reason will be described below. For example, in comparison of the experimental results for the ball rolling groove 3 of FIG. 4 having the groove width of 6 mm and the groove depth of 0.045 mm and the ball rolling groove 3 of FIG. 6 having the groove width of 8 mm and the groove depth of 0.044 mm, although the ball rolling groove 3 of FIG. 4 is substantially similar to the ball rolling groove 3 of FIG. 6 in the groove depth, the ball rolling groove 3 of FIG. 6 is larger than the ball rolling groove of FIG. 4 in the groove width, so that the golf ball B would hardly break away from the ball rolling groove 3 in the ball rolling groove 3 of FIG. 6. However, actually the ball rolling groove 3 of FIG. 6 has the higher percentage in which the golf ball B breaks away from the ball rolling groove 3.

This is attributed to the following facts. That is, in the ball rolling groove 3 of FIG. 4, the curvature radius in the transverse section is smaller, the side face has a steep slope, and the golf ball B is rebounded by the side face having the steep slope, thereby preventing the golf ball B from breaking away from the ball rolling groove 3, when the golf ball B almost breaks away from the ball rolling groove 3. Thus, when the error θ of the ball hitting angle is set at the desired value, the adjustment can be made by changing the curvature radius of the side face of the ball rolling groove 3 such that the golf ball B breaks away from the ball rolling groove 3.

Accordingly, when the transverse sectional shape of the ball rolling groove 3 is formed into the circular shape as shown in FIGS. 4 and 5, in the case where the ball rolling groove 3 has the groove width of 5 mm to 9 mm while the error θ of the ball hitting angle is not more than 2 degrees, the percentage in which the golf ball B breaks away from the ball rolling groove 3 is large. However, when the transverse sectional shape of the ball rolling groove 3 is formed into the elliptical shape as shown in FIG. 8, even if the error θ of the ball hitting angle is not lower than 2 degrees, the golf ball B hardly breaks away from the ball rolling groove 3. Thus, even if the error θ of the ball hitting angle is not more than 2 degrees, the transverse sectional shape of the ball rolling groove 3 is formed into the elliptical shape such that the golf ball B does not break away from the ball rolling groove 3, which allows the putting trainer of the second embodiment to be utilized for the putting trainings of the beginner and intermediate golfer.

FIG. 9 shows a third embodiment. The third embodiment is characterized in that the transverse sectional shape of the ball rolling groove 3 is formed into a trapezoidal shape by a flat surface 21 located in the groove bottom and slopes 22 rising from both sides of the flat surface 21. In the third embodiment, a rising angle of the slope 22 is adjusted as follows; even if the error θ of the ball hitting angle is not lower than 2 degrees, the golf ball B is rebounded by hitting the slope 22 of the ball rolling groove 3, and the golf ball B can be rolled in the ball rolling groove 3 while hardly breaking away from the ball rolling groove 3.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flat view of a putting trainer according to an embodiment of the invention.

FIG. 2 is a transverse sectional view of FIG. 1.

FIG. 3 is a left side view of FIG. 1 showing a state in which a golf ball is placed in the ball rolling groove.

FIG. 4 is a table showing experimental results.

FIG. 5 is a table showing experimental results.

FIG. 6 is a table showing experimental results.

FIG. 7 is a view explaining the action showing a state in which a golf ball is placed on the lawn.

FIG. 8 is a transverse sectional view of a ball rolling groove (second embodiment).

FIG. 9 is a transverse sectional view of a ball rolling groove (third embodiment).

FIG. 10 is a view showing a positional relationship between the putter, golf ball, and hole.

FIG. 11 is a view showing an appearance of a putting trainer (conventional technique).

FIG. 12 is a transverse sectional view of FIG. 11 (conventional technique).

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 putting trainer     -   2 base     -   3 ball rolling groove     -   4 mark     -   7 trimming surface     -   7 a step     -   8 down sloping surface     -   B golf ball     -   S lawn glass     -   θ error of ball hitting angle 

1. A golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along a ball rolling groove, the golf putting trainer being characterized in that the ball rolling groove has a groove width of 9 mm to 5 mm, a transverse sectional shape of the ball rolling groove is formed into a gently concave curved surface in which the golf ball is supported at one point, and a percentage in which the golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force, with which the golf ball is rolled to about 1.5 m to 2 m on the green, is applied.
 2. A golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along the ball rolling groove, the golf putting trainer being characterized in that the ball rolling groove has a groove width of 12 mm to 10 mm, a transverse sectional shape of the ball rolling groove is formed into a gently concave curved surface in which a golf ball is supported at one point, and the percentage in which a golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error not more than 2 degrees when a putting force with which a golf ball is rolled to about 1.5 m to 2 m on green is applied.
 3. The golf putting trainer according to claim 1, characterized in that the curved surface is formed into an arc surface whose section becomes an arc shape.
 4. The golf putting trainer according to claim 1, characterized in that the curved surface is formed into an elliptical surface whose section becomes an elliptical shape.
 5. The golf putting trainer according to claim 1, characterized in that the curved surface includes a flat surface located in a groove bottom of the ball rolling groove and a slope rising from both sides of the flat surface.
 6. The golf putting trainer according to claim 1, characterized in that flat trimming surfaces are provided along groove edges on both sides of a ball rolling groove.
 7. The golf putting trainer according to claim 6, characterized in that a downward sloping surface is formed from an edge of a flat surface to an edge of a plate material.
 8. The golf putting trainer according to claim 1, characterized in that at least inside the ball rolling groove is lusterless.
 9. The golf putting trainer according to claim 1, characterized in that a mark having a diameter smaller than a diameter of a golf ball is provided around a ball placing portion.
 10. A golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along a ball rolling groove, the golf putting trainer being characterized in that a transverse sectional shape of the ball rolling groove is formed into an arc shape having a curvature radius of 100 mm, the ball rolling groove has a groove width of 9 mm to 5 mm, and a percentage in which a golf ball breaks away from a ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force with which a golf ball is rolled to about 1.5 m to 2 m on green is applied.
 11. A golf putting trainer in which a ball rolling groove is formed, a ball placing portion is provided on a base-end side of the ball rolling groove, and a golf ball placed on the ball placing portion is putted and rolled along a ball rolling groove, the golf putting trainer being characterized in that a transverse sectional shape of the ball rolling groove is formed into an arc shape having a curvature radius of 60 mm, the ball rolling groove has a groove width of 9 mm to 5 mm, and a percentage in which a golf ball breaks away from the ball rolling groove is decreased in a ball hitting angle having an error lower than 2 degrees when a putting force with which a golf ball is rolled to about 1.5 m to 2 m on green is applied.
 12. The golf putting trainer according to claim 1, characterized in that the golf putting trainer is made of metal.
 13. The golf putting trainer according to claim 2, characterized in that the curved surface is formed into an arc surface whose section becomes an arc shape.
 14. The golf putting trainer according to claim 2, characterized in that the curved surface is formed into an elliptical surface whose section becomes an elliptical shape.
 15. The golf putting trainer according to claim 2, characterized in that the curved surface includes a flat surface located in a groove bottom of the ball rolling groove and a slope rising from both sides of the flat surface.
 16. The golf putting trainer according to claim 2, characterized in that flat trimming surfaces are provided along groove edges on both sides of a ball rolling groove.
 17. The golf putting trainer according to claim 2, characterized in that at least inside the ball rolling groove is lusterless.
 18. The golf putting trainer according to claim 2, characterized in that a mark having a diameter smaller than a diameter of a golf ball is provided around a ball placing portion.
 19. The golf putting trainer according to claim 2, characterized in that the golf putting trainer is made of metal. 